6,320 research outputs found

    Indoor environmental quality in offices and risk of health and productivity complaints at work: A literature review

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    Many service jobs are carried out in modern offices, with individual offices being increasingly replaced by open-plan settings. The high number of adult people working in office buildings, in most situations sharing the work-place with many others during a considerable part of their daily time, highlights the importance of providing adequate guidance to ensure the quality of office environments. This paper aims to summarize existing data on modern offices' indoor environmental quality (IEQ) conditions in terms of air pollution (volatile organic compounds (VOC), particulate matter and inorganic pollutants), thermal comfort, lighting and acoustics and the respective associations with health and productivity-related outcomes in workers. Evidence shows that al-though many offices present acceptable IEQ, some office settings can have levels of air pollutants, hygrothermal conditions/thermal comfort and illuminance that do not comply with the existing international standards and recommendations. In addition, findings suggest the existence of significant associations between the assessed IEQ indicators and the risk of detrimental effects on health and productivity of office workers. In particular, airborne particles, CO2, O 3 and thermal comfort were linked with the prevalence of sick building syndrome symptoms. Poor lighting and acoustical quality have also been associated with malaise and physiological stress among office workers. Similarly, better productivity levels have been registered for good indoor air quality conditions, in terms of VOC, airborne particles and CO2. Overall, the evidence revised in this work suggests that for promoting health and productivity recommendations for office building managers include actions to ensure that: i) all relevant IEQ indicators are periodically controlled to ensure that levels comply with recommended limit values; ii) declared in-door pollution sources are avoided; iii) adequate ventilation and acclimatization strategies are implemented; and iv) there is the possibility of conduct personalized adjustments to environmental conditions (following workers' preferences).The authors gratefully acknowledge Fundacao para a Ciencia e nologia (FCT) for the financial support of FF through the PhD BD/6521/2020

    Weaknesses in motivation and in establishing a meritocratic system: A portrait of the Portuguese public administration

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    The complexities of Public Administration have gained the growing attention of scholars around the world, mainly due to the impacts of the reforms implemented under the doctrine of New Public Management (which aims to apply concepts and practices of private management in public management) on civil servants. The aim of this study is to find out how Portuguese citizens evaluate the Portuguese Public Administration under the aspects of bureaucracy, organisation of human resources, innovation, skills and attitudes of civil servants, its motivation and recognition; and to verify if there are differences of opinion between respondents working in public sector and respondents from other sectors. This study follows a quali-quantitative approach, and data were collected through an online survey in the period from June to December 2020. The survey was answered by 1119 citizens from all districts of Portugal. The main findings reveal a still high level of bureaucracy in the Portuguese Public Administration; weaknesses in the management of human resources, namely regarding the motivation and recognition of civil servants; and difficulties in the establishment of a meritocratic system of recruitment and performance evaluation of civil servants. Statistically significant evaluation differences (chi-square test and non-parametric Mann–Whitney U tests, involving five hypotheses) were found between the public sector and other sectors, except for the motivation variable.info:eu-repo/semantics/publishedVersio

    Evaluation of the essential oil and tea produced from Baccharis myriocephala leaves.

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    Abstract: Baccharis myriocephala is a carqueja species less studied than other Baccharis species. This study evaluated the chemical composition, toxicological and antioxidant potentials of the essential oils and infusions of B. myriocephala. Essential oils (hydrodistillation) and the volatile fractions of infusions (SPE) were analyzed by chromatographic techniques. The TPC and TFC of the infusions, and the antioxidant activities of essential oils and infusions were measured by spectrophotometry; their toxicological potentials were evaluated by Artemia salina bioassay (ASB). Twenty-eight terpenic compounds were identified in the essential oils, fourteen of them for the first time. Nine compounds were identified in the volatile fraction of the infusions, and seven of them were absent in essential oils. Infusions [IC50(DPPH) = 2.21 mg mL−1] are better antioxidants than the essential oils [IC50(DPPH) = 40.37 mg mL−1]. The essential oils were considered highly cytotoxic (LD50 = 26.64 μg mL−1), according to the ASB

    On the Formation of Copper Linear Atomic Suspended Chains

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    We report high resolution transmission electron microscopy and classical molecular dynamics simulation results of mechanically stretching copper nanowires conducting to linear atomic suspended chains (LACs) formation. In contrast with some previous experimental and theoretical work in literature that stated that the formation of LACs for copper should not exist our results showed the existence of LAC for the [111], [110], and [100] crystallographic directions, being thus the sequence of most probable occurence.Comment: 4 pages, 3 figure

    Mapeamento de QTL para qualidade de grãos de uma população de arroz de terras altas.

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    Nesse estudo, o mapeamento de QTL para atributos de qualidade de grãos da população BRS Primavera x Douradão (PxD) terá a finalidade de detectar regiões específicas no genoma do arroz responsáveis por caracteres quantitativos que interferem na qualidade de grãos

    New method to study stochastic growth equations: a cellular automata perspective

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    We introduce a new method based on cellular automata dynamics to study stochastic growth equations. The method defines an interface growth process which depends on height differences between neighbors. The growth rule assigns a probability pi(t)=ρp_{i}(t)=\rho exp[κΓi(t)][\kappa \Gamma_{i}(t)] for a site ii to receive one particle at a time tt and all the sites are updated simultaneously. Here ρ\rho and κ\kappa are two parameters and Γi(t)\Gamma_{i}(t) is a function which depends on height of the site ii and its neighbors. Its functional form is specified through discretization of the deterministic part of the growth equation associated to a given deposition process. In particular, we apply this method to study two linear equations - the Edwards-Wilkinson (EW) equation and the Mullins-Herring (MH) equation - and a non-linear one - the Kardar-Parisi-Zhang (KPZ) equation. Through simulations and statistical analysis of the height distributions of the profiles, we recover the values for roughening exponents, which confirm that the processes generated by the method are indeed in the universality classes of the original growth equations. In addition, a crossover from Random Deposition to the associated correlated regime is observed when the parameter κ\kappa is varied.Comment: 6 pages, 7 figure

    Primary spinal glioblastoma: A case report and review of the literature

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    Primary spinal glioblastoma (GBM) is a rare disease, with an aggressive course and a poor prognosis. We report a case of a 19-year-old male with a 4-week history of progressive weakness in both lower limbs, which progressed to paraparesis with a left predominance and difficulty in initiating urination over a week. Spine magnetic resonance imaging (MRI) showed an intramedullary expansile mass localised between T6 and T11. We performed a laminotomy and laminoplasty between T6 and T11 and the tumour was partially removed. Histopathological study was compatible with GBM. The patient was administered focal spine radiotherapy with chemotherapy with temozolamide. Serial MRI performed after the initial surgery demonstrated enlargement of the enhancing mass from T3 to T12 and subarachnoid metastatic deposits in C2 and C4, the pituitary stalk, interpeduncular cistern, left superior cerebellar peduncle and hydrocephalus. We review the literature with regard to the disease and treatment options, and report the unique features of this case. Primary spinal GBM is an extremely rare entity with a poor prognosis and a short survival time. An aggressive management of the different complications as they arise and improvement of current modes of treatment and new treatment options are required to improve survival and ensure better quality of life

    Application of exopolysaccharides to optimize the performance of ceramic bodies in the unidirectional dry pressing process

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    Ceramic industry represents an important sector of economic activity in the European countries and involves complex and numerous manufacturing processes. The unidirectional dry pressing process includes milling and stirring of raw materials (mainly clay and talc minerals) in aqueous suspensions, followed by spray drying to remove excess water obtaining spray-dried powders further subjected to dry pressing process (conformation). However, spray-dried ceramic powders exhibit an important variability in their performance when subjected to the dry pressing process, particularly in the adhesion to the mold and mechanical strength, affecting the quality of the final conformed ceramic products. Therefore, several synthetic additives (deflocculants, antifoams, binders, lubricants and plasticizers) are introduced in the ceramic slips to achieve uniform and homogeneous pastes, conditioning their rheological properties. However, an important variability associated with the performance of the conformed products is still reported. Exopolysaccharides or Extracellular Polymeric Substances (EPS) are polymers excreted by living organisms, such as bacteria, fungi and algae, which may confer unique and potentially interesting properties with potential industrial uses, such as viscosity control, gelation, and flocculation. Polysaccharides, such as pullulan, gellan, carrageenan and xanthan have found a wide range of applications in food, pharmaceutical, petroleum, and in other industries. The aim of this study was the assessment of exopolysaccharides as natural additives to optimize the performance of spray-dried ceramic powders during the unidirectional dry pressing process, replacing the synthetic additives used in the ceramic production process. Six exopolysaccharides, namely pullulan, gellan, xanthan gum, κappa- and iota-carrageenan, and guar gum were tested in steatite-based spray-dried ceramic powders at different concentrations. Subsequently, these ceramic powders were submitted to unidirectional dry pressing process (conformation) and the green conformed bodies were tested on the following properties: mechanical flexural strength and adhesion/disaggregation of the conformed material. The binding state of polysaccharides and mineral grains was evaluated by field emission scanning electron microscopy (FESEM). Our data showed that xanthan gum and pullulan were the most effective polysaccharides in improving the performance of spray-dried ceramic powders during unidirectional dry pressing process, in comparison to the control steatite-based ceramic bodies containing synthetic additives. In addition, these polysaccharides yielded the best cost-benefit relationship, representing an eco-friendly and cost-effective alternative to synthetic additives used in technical ceramics industry. Hence, this study has contributed to define a new and sustainable strategy to improve the performance of ceramic materials during unidirectional dry pressing process, reduce production costs and minimize environmental impact. Acknowledgments: This study was financed by Portuguese funds through FCT- Fundação para a Ciência e a Tecnologia (project EXPL/CTM-CER/0637/2012) and supported by Rauschert Portuguesa, SA.This study was financed by Portuguese funds through FCT- Fundação para a Ciência e a Tecnologia (project EXPL/CTM-CER/0637/2012) and supported by Rauschert Portuguesa, SA.Peer Reviewe

    Universality class of criticality in the restricted primitive model electrolyte

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    The 1:1 equisized hard-sphere electrolyte or restricted primitive model has been simulated via grand-canonical fine-discretization Monte Carlo. Newly devised unbiased finite-size extrapolation methods using temperature-density, (T, rho), loci of inflections, Q = ^2/ maxima, canonical and C_V criticality, yield estimates of (T_c, rho_c) to +- (0.04, 3)%. Extrapolated exponents and Q-ratio are (gamma, nu, Q_c) = [1.24(3), 0.63(3); 0.624(2)] which support Ising (n = 1) behavior with (1.23_9, 0.630_3; 0.623_6), but exclude classical, XY (n = 2), SAW (n = 0), and n = 1 criticality with potentials phi(r)>Phi/r^{4.9} when r \to \infty

    Common molecular pathways involved in human CD133+/CD34+ progenitor cell expansion and cancer

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    <p>Abstract</p> <p>Background</p> <p>Uncovering the molecular mechanism underlying expansion of hematopoietic stem and progenitor cells is critical to extend current therapeutic applications and to understand how its deregulation relates to leukemia. The characterization of genes commonly relevant to stem/progenitor cell expansion and tumor development should facilitate the identification of novel therapeutic targets in cancer.</p> <p>Methods</p> <p>CD34+/CD133+ progenitor cells were purified from human umbilical cord blood and expanded <it>in vitro</it>. Correlated molecular changes were analyzed by gene expression profiling using microarrays covering up to 55,000 transcripts. Genes regulated during progenitor cell expansion were identified and functionally classified. Aberrant expression of such genes in cancer was indicated by <it>in silico </it>SAGE. Differential expression of selected genes was assessed by real-time PCR in hematopoietic cells from chronic myeloid leukemia patients and healthy individuals.</p> <p>Results</p> <p>Several genes and signaling pathways not previously associated with <it>ex vivo </it>expansion of CD133+/CD34+ cells were identified, most of which associated with cancer. Regulation of MEK/ERK and Hedgehog signaling genes in addition to numerous proto-oncogenes was detected during conditions of enhanced progenitor cell expansion. Quantitative real-time PCR analysis confirmed down-regulation of several newly described cancer-associated genes in CD133+/CD34+ cells, including <it>DOCK4 </it>and <it>SPARCL1 </it>tumor suppressors, and parallel results were verified when comparing their expression in cells from chronic myeloid leukemia patients</p> <p>Conclusion</p> <p>Our findings reveal potential molecular targets for oncogenic transformation in CD133+/CD34+ cells and strengthen the link between deregulation of stem/progenitor cell expansion and the malignant process.</p
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